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1.
Microb Pathog ; 196: 106949, 2024 Sep 16.
Artículo en Inglés | MEDLINE | ID: mdl-39293725

RESUMEN

The antimicrobial activity of crude and purified L-glutaminase (EC 3.5.1.2), obtained from Lactobacillus gasseri, was evaluated against multidrug-resistant Pseudomonas aeruginosa in the in vivo vaginosis condition. The L-glutaminase possessed significant antimicrobial and anti-biofilm formation activity against multi-drug resistance P. aeruginosa, which were confirmed in the BALBc rat vaginosis model, together with its effects on the immunological and histopathological aspects. The untreated animals showed heavy vaginitis, characterized by sub-epithelial edema and infiltration of mononuclear leukocytes, perivascular heavy inflammatory cells infiltration in the vaginal tissue, and moderate stromal edema. However, the L-glutaminase treatment exhibited no changes in vaginal tissue structure with normal appearance of the epithelium and lamina propria with marked repair of the vaginal section when compared with normal, uninfected, control group A. The immunomodulatory actions of the L-glutaminase were confirmed by observance of higher concentrations of tumor necrosis factor-γ (TNF-γ), and interleukin -12 (IL-12) in treated animals, while the interleukin-10 (IL-10) was higher in the infected, untreated animals' sera samples. Therefore, the L-glutaminase showed corrective and healing actions, which were observed through histopathological observations of the vaginal tissue. The investigations led to imply that L-glutaminase may have the potential to be an effective antimicrobial agent for preventing and inhibiting bacterial growth, as well as inhibiting the biofilm formation in the P. aeruginosa-originated vaginosis. The observations may be of promising value for future clinical use.

2.
J Oral Microbiol ; 16(1): 2373040, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38974504

RESUMEN

Background: Curcumin is a multi-functional polyphenol with anti-bacterial and anti-inflammatory effects and may have potential for treatment of periodontal diseases. The present study was conducted to examine the molecular basis of the anti-bacterial effect of curcumin against Porphyromonas gingivalis using metabolome analysis. Materials and Methods: P. gingivalis were incubated with 10 µg/mL curcumin, and then metabolites were analyzed with CE-TOF/MS. Expression levels of sigma factors were also evaluated using RT-PCR assays. The activities of dipeptidyl peptidases (DPPs) were assessed by examining the degradation reactions of MCA-labeled peptides. Results: The relative amounts of various glycogenic amino acids were significantly decreased when P. gingivalis was incubated with curcumin. Furthermore, the metabolites on the amino acid degradation pathway, including high-energy compounds such as ATP, various intermediate metabolites of RNA/DNA synthesis, nucleoside sugars and amino sugars were also decreased. Additionally, the expression levels of sigma-54 and sigma-70 were significantly decreased, and the same results as noted following nutrient starvation. Curcumin also significantly suppressed the activities of some DPPs, while the human DPP-4 inhibitors markedly inhibited the growth of P. gingivalis and activities of the DPPs. Conclusions: Curcumin suppresses the growth of P. gingivalis by inhibiting DPPs and also interferes with nucleic acid synthesis and central metabolic pathways, beginning with amino acid metabolism.

3.
BMC Plant Biol ; 24(1): 647, 2024 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-38977968

RESUMEN

BACKGROUND: The ginseng endophyte Paenibacillus polymyxa Pp-7250 (Pp-7250) has multifaceted roles such as preventing ginseng diseases, promoting growth, increasing ginsenoside accumulation, and degrading pesticide residues, however, these effects still have room for improvements. Composite fungicides are an effective means to improve the biocontrol effect of fungicides, but the effect of Pp-7250 in combination with its symbiotic bacteria on ginseng needs to be further investigated, and its mechanism of action has not been elucidated. In this study, a series of experiments was conducted to elucidate the effect of Paenibacillus polymyxa and Bacillus cereus co-bacterial agent on the yield and quality of understory ginseng, and to investigate their mechanism of action. RESULTS: The results indicated that P. polymyxa and B. cereus co-bacterial agent (PB) treatment improved ginseng yield, ginsenoside accumulation, disease prevention, and pesticide degradation. The mechanism is that PB treatment increased the abundance of beneficial microorganisms, including Rhodanobacter, Pseudolabrys, Gemmatimonas, Bacillus, Paenibacillus, Cortinarius, Russula, Paecilomyces, and Trechispora, and decreased the abundance of pathogenic microorganisms, including Ellin6067, Acidibacter, Fusarium, Tetracladium, Alternaria, and Ilyonectria in ginseng rhizosphere soil. PB co-bacterial agents enhanced the function of microbial metabolic pathways, biosynthesis of secondary metabolites, biosynthesis of antibiotics, biosynthesis of amino acids, carbon fixation pathways in prokaryotes, DNA replication, and terpenoid backbone biosynthesis, and decreased the function of microbial plant pathogens and animal pathogens. CONCLUSION: The combination of P. polymyxa and B. cereus may be a potential biocontrol agent to promote the resistance of ginseng to disease and improve the yield, quality, and pesticide degradation.


Asunto(s)
Ginsenósidos , Paenibacillus polymyxa , Panax , Enfermedades de las Plantas , Rizosfera , Panax/microbiología , Panax/crecimiento & desarrollo , Panax/efectos de los fármacos , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/prevención & control , Bacillus cereus/efectos de los fármacos , Bacillus cereus/crecimiento & desarrollo , Microbiología del Suelo , Endófitos/fisiología , Endófitos/efectos de los fármacos , Microbiota/efectos de los fármacos
4.
Antibiotics (Basel) ; 13(6)2024 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-38927203

RESUMEN

Management of suspected early-onset sepsis (EOS) is undergoing continuous evolution aiming to limit antibiotic overtreatment, yet current data on the level of overtreatment are only available for a select number of countries. This study aimed to determine antibiotic initiation and continuation rates for suspected EOS, along with the incidence of culture-proven EOS in The Netherlands. In this retrospective study from 2019 to 2021, data were collected from 15 Dutch hospitals, comprising 13 regional hospitals equipped with Level I-II facilities and 2 academic hospitals equipped with Level IV facilities. Data included birth rates, number of neonates started on antibiotics for suspected EOS, number of neonates that continued treatment beyond 48 h and number of neonates with culture-proven EOS. Additionally, blood culture results were documented. Data were analysed both collectively and separately for regional and academic hospitals. A total of 103,492 live-born neonates were included. In 4755 neonates (4.6%, 95% CI 4.5-4.7), antibiotic therapy was started for suspected EOS, and in 2399 neonates (2.3%, 95% CI 2.2-2.4), antibiotic treatment was continued beyond 48 h. Incidence of culture-proven EOS was 1.1 cases per 1000 live births (0.11%, 95% CI 0.09-0.14). Overall, for each culture-proven EOS case, 40.6 neonates were started on antibiotics and in 21.7 neonates therapy was continued. Large variations in treatment rates were observed across all hospitals, with the number of neonates initiated and continued on antibiotics per culture-proven EOS case varying from 4 to 90 and from 4 to 56, respectively. The high number of antibiotic prescriptions compared to the EOS incidence and wide variety in clinical practice among hospitals in The Netherlands underscore both the need and potential for a novel approach to the management of neonates with suspected EOS.

5.
Antibiotics (Basel) ; 13(5)2024 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-38786117

RESUMEN

Early-onset sepsis (EOS) is a rare but profoundly serious bacterial infection. Neonates at risk of EOS are often treated with antibiotics. The start of empiric antibiotic therapy can successfully be reduced by the implementation of the EOS calculator. However, once started, antibiotic therapy is often continued despite a negative blood culture. To decrease the burden of antibiotic therapy, it is necessary to know whether the clinician's reasons are based on objective factors. Therefore, we performed a retrospective single-centre cohort study to identify the factors associated with prolongation of antibiotic therapy in neonates with suspected EOS but a negative blood culture. Maternal, clinical, and laboratory data of neonates with a gestational age of ≥32 weeks, admitted between January 2019 and June 2021, were collected. Among neonates with a negative blood culture, we compared neonates with prolonged (≥3 days) to neonates with discontinued (<3 days) antibiotic therapy. The clinician's reported reasons for prolonging therapy were explored. Blood cultures were positive in 4/146 (2.7%), negative in 131/146 (89.7%), and not obtained in 11/146 (7.5%) of the neonates. The incidence of EOS was 0.7 per 1000 neonates. Of the 131 neonates with a negative blood culture, 47 neonates (35.9%) received prolonged antibiotic therapy. In the prolonged group, the mean gestational age was higher (38.9 versus 36.8 weeks), and spontaneous preterm birth was less prevalent (21.3% versus 53.6%). Prolonged treatment was associated with late onset of respiratory distress, respiratory rate, hypoxia, apnoea and bradycardia, pale appearance, behavioural change, and elevated CRP levels. The most reported reasons were clinical appearance (38.3%), elevated CRP levels (36.2%), and skin colour (10.6%). Prolonging empiric antibiotic therapy despite a negative blood culture is common in suspected EOS. Clinical signs associated with prolongation are uncommon and the reported reasons for prolongation contain subjective assessments and arbitrary interpretations that are not supported by the guideline recommendations as arguments for prolonged therapy.

6.
J Hazard Mater ; 472: 134438, 2024 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-38718504

RESUMEN

Construction of an efficient bio-reductive dechlorination system remains challenging due to the narrow ecological niche and low-growth rate of organohalide-respiring bacteria during field remediation. In this study, a biochar-based organohalide-respiring bacterial agent was obtained, and its performance and effects on indigenous microbial composition, diversity, and inter-relationship in soil were investigated. A well-performing material, Triton X-100 modified biochar (BC600-TX100), was found to have the superior average pore size, specific surface area and hydrophicity, compared to other materials. Interestingly, Pseudomonas aeruginosa CP-1, which is capable of 2,4,6-TCP dechlorination, showed a 348 times higher colonization cell number on BC600-TX100 than that of BC600 after 7 d. Meanwhile, the dechlorination rate in soil showed the highest (0.732 d-1) in the BC600-TX100 bacterial agent than in the other agents. The long-term performance of the BC600-TX100 OHRB agent was also verified, with a stable dechlorination activity over six cycles. Soil microbial community analysis found the addition of the BC600-TX100 OHRB agent significantly increased the relative abundance of genus Pseudomonas from 1.53 % to 11.2 %, and Pseudomonas formed a close interaction relationship with indigenous microorganisms, creating a micro-ecological environment conducive to reductive dechlorination. This study provides a feasible bacterial agent for the in-situ bioremediation of soil contaminated organohalides. ENVIRONMENTAL IMPLICATION: Halogenated organic compounds are a type of toxic, refractory, and bio-accumulative persistent compounds widely existed in environment, widely detected in the air, water, and soil. In this study, we provide a feasible bacterial agent for the in-situ bioremediation of soil contaminated halogenated organic compounds. The application of biochar provides new insights for "Turning waste into treasure", which meets with the concept of green chemistry.


Asunto(s)
Biodegradación Ambiental , Carbón Orgánico , Clorofenoles , Microbiología del Suelo , Contaminantes del Suelo , Carbón Orgánico/química , Contaminantes del Suelo/metabolismo , Contaminantes del Suelo/química , Clorofenoles/metabolismo , Clorofenoles/química , Halogenación , Pseudomonas aeruginosa/metabolismo , Bacterias/metabolismo
7.
Bioresour Technol ; 400: 130681, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38599350

RESUMEN

Excavating nitrogen-fixing bacteria with high-temperature tolerance is essential for the efficient composting of animal dung. In this study, two strains of thermophilic nitrogen-fixing bacteria, NF1 (Bacillus subtilis) and NF2 (Azotobacter chroococcum), were added to cow dung compost both individually (NF1, NF2) and mixed together (NF3; mixing NF1 and NF2 at a ratio of 1:1). The results showed that NF1, NF2, and NF3 inoculants increased the total Kjeldahl nitrogen level by 38.43%-55.35%, prolonged the thermophilic period by 1-13 d, increased the seed germination index by 17.81%, and the emissions of NH3 and N2O were reduced by 25.11% and 42.75%, respectively. Microbial analysis showed that Firmicutes were the predominant bacteria at the thermophilic stage, whereas Chloroflexi, Proteobacteria, and Bacteroidetes were the predominant bacteria at the mature stage. These results confirmed that the addition of the isolated strains to cow dung composting improved the bacterial community structure and benefited nitrogen retention.


Asunto(s)
Compostaje , Nitrógeno , Animales , Bovinos , Estiércol/microbiología , Heces/microbiología , Bacterias Fijadoras de Nitrógeno/metabolismo , Bacillus subtilis , Temperatura , Germinación
8.
J Int Med Res ; 52(3): 3000605231213760, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38483146

RESUMEN

Porphyromonas gingivalis, a gram-negative oral anaerobe among more than more than 500 bacterial species that colonizing the oral cavity, is involved in the pathogenesis and prototypic polybacterial consortium of periodontitis. It is mainly found in oral infections and rarely present in other organ diseases. Here, we describe a 43-year-old man with underlying diabetes who developed hematogenous disseminated severe pneumonia after P. gingivalis had invaded the blood. Next-generation sequencing of early alveolar lavage fluid and blood samples confirmed the diagnosis. The patient's lung infection improved after targeted antimicrobial treatment. He was successfully weaned from ventilatory support and transferred to the general ward. This case illustrates bacterial entry into the bloodstream of a patient with diabetes who had periodontal disease but did not maintain oral hygiene, leading to severe pneumonia. Periodontal disease is often ignored by the public, and it is difficult for critical care physicians to link severe pneumonia with periodontal disease. Thus, this case represents an important warning to critical care clinicians.


Asunto(s)
Diabetes Mellitus , Enfermedades Periodontales , Periodontitis , Neumonía , Masculino , Humanos , Adulto , Porphyromonas gingivalis , Periodontitis/complicaciones , Periodontitis/terapia , Neumonía/complicaciones
9.
J Biomol Struct Dyn ; : 1-12, 2024 Jan 04.
Artículo en Inglés | MEDLINE | ID: mdl-38174403

RESUMEN

Staphylococcus aureus is one of the most frequently food-contaminated incidence of healthcare-associated Gram-positive bacteria. The antibacterial function and mechanism of phenolic compounds from dandelion are still unclear. Herein, this work aims to screen one of dandelion phenolic extracts with the strongest antibacterial function from its organ such as flower, stem, leaf and root, and to reveal its antibacterial mechanism. The results indicated dandelion flower phenolic extract (DFPE) containing the highest content of caffeic acid, followed by luteolin and luteolin-7-O-glucoside. They, especially caffeic acid and luteolin-7-O-glucoside, played a key role in making the bacterial cellular-membrane ruptured against the bacteria. The leakage of the intracellular substances (adenosine triphosphate and Na+-K+ ATPase) was further confirmed. Conventional hydrogen bond, pi-anion, pi-alkyl were involved in the interaction between caffeic acid or luteolin-7-O-glucoside and Na+-K+ ATPase. Additionally, the dynamic equilibrium of the liganded ATPase complex were achieved after 105 ns, and the lower values from the radius of gyration and solvent accessible surface area in the complex demonstrated the highly tight and compact structure of the liganded protein. The highest free binding energy (ΔGbind = -47.80 kJ/mol) between Na+-K+ ATPase and luteolin-7-O-glycloside was observed. Overall, DFPE can be used as an effective anti-bacterial agent due to the contribution of its bioactive ingredients such as caffeic acid and luteolin-7-O-glucoside for membrane-breaking.Communicated by Ramaswamy H. Sarma.

10.
J Int Med Res ; 51(12): 3000605231206959, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38082462

RESUMEN

Nocardia pseudobrasiliensis is a new taxon constituting an emerging species of human pathogenic Nocardia, which shares morphological features with N. brasiliensis. However, N. pseudobrasiliensis is more invasive and more easily disseminated, and it exhibits distinctive antibiotic susceptibility. Few clinical cases related to N. pseudobrasiliensis infection have been reported, and N. pseudobrasiliensis hydrarthrosis has not been described. Here, we analyzed the case information, diagnostic process, treatment, and prognosis of a patient with N. pseudobrasiliensis hydrarthrosis who received treatment in Zhejiang Provincial People's Hospital. Magnetic resonance imaging showed joint cavity effusion and soft tissue swelling with high signal on proton density-fat saturated images and low signal on T1-weighted images. Oil microscopy revealed abundant acid-fast-positive filaments in hydrarthrosis puncture fluid. The pathogen was identified as N. pseudobrasiliensis by matrix-assisted laser desorption ionization-time of flight mass spectrometry. In contrast to the 100% ciprofloxacin resistance displayed by N. brasiliensis, this clinical isolate of N. pseudobrasiliensis was completely susceptible. In summary, this is the first report of N. pseudobrasiliensis in joint effusion from a patient with arthritis.


Asunto(s)
Artritis , Hidrartrosis , Nocardiosis , Nocardia , Humanos , Nocardiosis/complicaciones , Nocardiosis/diagnóstico , Nocardiosis/tratamiento farmacológico
11.
J Infect Dis ; 2023 Nov 08.
Artículo en Inglés | MEDLINE | ID: mdl-37946558

RESUMEN

BACKGROUND: For simultaneous prediction of phenotypic drug susceptibility test (pDST) for multiple anti-tuberculosis drugs, the whole genome sequencing (WGS) data can be analyzed using either catalogue-based approach, wherein one causative mutation suggests resistance, (e.g., WHO catalog) or non-catalogue-based approach using complicated algorithm (e.g., TB-profiler, machine learning). The aim was to estimate the predictive ability of WGS-based tests with pDST as the reference, and to compare the two approaches. METHODS: Following the systematic literature search, the diagnostic test accuracies for 14 drugs were pooled using a random-effect bivariate model. RESULTS: Out of 779 articles, 44 articles with 16,821 specimens for meta-analysis and 13 articles not for meta-analysis were adopted. The areas under summary receiver operating characteristic curve suggested "excellent" (0.97-1.00) for 2 drugs (isoniazid 0.975, rifampicin 0.975), "very good" (0.93-0.97) for 8 drugs (pyrazinamide 0.946, streptomycin 0.952, amikacin 0.968, kanamycin 0.963, capreomycin 0.965, para-aminosalicylic acid 0.959, levofloxacin 0.960, ofloxacin 0.958), and "good" (0.75-0.93) for 4 drugs (ethambutol 0.926, moxifloxacin 0.896, ethionamide 0.878, prothionamide 0.908). The non-catalogue-based and catalogue-based approaches had similar ability for all drugs. CONCLUSION: WGS accurately identifies isoniazid and rifampicin resistance. For most drugs, positive WGS results reliably predict pDST positive. The two approaches had similar ability.

12.
Heliyon ; 9(8): e18759, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37576200

RESUMEN

Two new developments of antibacterial agents, a series of benzofuran-triazine based compounds (8a-8h) were designed and synthesized. The derivatives were prepared through conventional chemical reactions and structurally characterized with FT-IR, 1H and 13C NMR techniques. The antibacterial activity of the synthesized derivatives was assessed against gram-positive bacterial strains (Bacillus subtilis, and Staphylococcus aureus) and gram-negative bacterial strains (Salmonella entritidis and Escherichia coli). Compound 8e, with the MIC value of 125-32 µg/µl against all the examined strains of bacteria, was the most active antibacterial compound. The synthesized derivatives were also studied for docking to the binding sites of dihydrofolate reductase (DHFR) receptor which has a key role in drug resistance associated with bacterial infections. The synthesized compounds showed good interaction with the targets through hydrogen bonding and hydrophobic interactions. According to antibacterial and docking studies, compound 8e could be introduced as a candidate for development of antibacterial compounds.

13.
Int J Biol Macromol ; 242(Pt 1): 124703, 2023 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-37141967

RESUMEN

The wide spectrum of applications provided by curcumin has attracted researchers worldwide to identify its molecular targets and employ it in various biomedical applications. The present research work focuses on the development of a Butea monosperma gum-based hydrogel encapsulated with curcumin and further employing it for two diverse applications, i.e., drug delivery and anti-bacterial application. A central composite design was utilized for the optimization of significant process variables to achieve maximum swelling. A maximum of 662 % swelling was attained at initiator (0.06 g), monomer (3 ml), crosslinker (0.08 g), solvent (14 ml), and time (60 s). Furthermore, the characterization of the synthesized hydrogel was performed via FTIR, SEM, TGA, H1-NMR, and XRD analysis. Various important properties like swelling rate under different solutions, water retention capacity, re-swelling capability, porosity, and density measurement suggested that the prepared hydrogel exhibited a highly stable crosslinked network with high porosity (0.23) and density (62.5 g/cm3) values. The encapsulation efficiency of curcumin in the hydrogel was reported to be 93 % and 87.3 %, respectively, wherein BM-g-poly(AA) âˆ¼ Cur exhibited excellent sustained pH-responsive site release of curcumin at two different pH values, with the maximum amount of release taking place at pH 7.4 (792 ppm) and a minimum at pH 5 (550 ppm) due to the lesser ionization of the functional groups present in the hydrogel at a lower pH value. Additionally, the results from the pH shock studies indicated our material to be stable and efficient even with fluctuations in pH, resulting in the optimal amount of drug release at each pH range. Furthermore, anti-bacterial studies revealed that the synthesized BM-g-poly(AA) âˆ¼ Cur was effective against both gram-negative and gram-positive bacteria, with maximum values of zones of inhibition of 16 mm in diameter, thereby showing the best results in comparison to the already developed matrices till date. As a result, the newly discovered BM-g-poly(AA) âˆ¼ Cur properties reflect the hydrogel network's suitability for drug release and anti-bacterial applications.


Asunto(s)
Butea , Curcumina , Curcumina/farmacología , Curcumina/química , Hidrogeles/química , Excipientes/química , Portadores de Fármacos/química , Liberación de Fármacos
14.
J Paediatr Child Health ; 59(5): 718-722, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-36999339

RESUMEN

AIM: To assess whether febrile neonates from the community received their first dose of intravenous antibiotics within 1 h from time of arrival, as per the regional paediatric sepsis pathway, at a tertiary combined adult/child emergency department in New Zealand. METHOD: Retrospective data were collected from January 2018 to December 2019 with 28 patients included. RESULTS: Mean time to first antibiotic dose for all neonates and those with serious bacterial infection was 3 h 20 min and 2 h 53 min respectively. No case used the paediatric sepsis pathway. A pathogen was identified in 19/28 (67%) neonates and 16/28 (57%) had clinical signs of shock. CONCLUSION: This study adds to Australasian data on community neonatal sepsis. Antibiotic administration was delayed for neonates with serious bacterial infection, clinical signs of shock and raised lactate. The reasons for delay are examined, with a number of potential areas for improvement identified.


Asunto(s)
Infecciones Bacterianas , Sepsis , Recién Nacido , Adulto , Humanos , Niño , Antibacterianos/uso terapéutico , Estudios Retrospectivos , Fiebre/tratamiento farmacológico , Sepsis/diagnóstico , Infecciones Bacterianas/tratamiento farmacológico , Infecciones Bacterianas/diagnóstico
15.
J Hazard Mater ; 449: 131015, 2023 05 05.
Artículo en Inglés | MEDLINE | ID: mdl-36801720

RESUMEN

A promising strategy for degrading persistent organic pollutants (POPs) in soil is amendment with nanomaterial-assisted functional bacteria. However, the influence of soil organic matter chemodiversity on the performance of nanomaterial-assisted bacterial agents remains unclear. Herein, different types of soil (Mollisol soil, MS; Ultisol soil, US; and Inceptisol soil, IS) were inoculated with a graphene oxide (GO)-assisted bacterial agent (Bradyrhizobium diazoefficiens USDA 110, B. diazoefficiens USDA 110) to investigate the association between soil organic matter chemodiversity and stimulation of polychlorinated biphenyl (PCB) degradation. Results indicated that the high-aromatic solid organic matter (SOM) inhibited PCB bioavailability, and lignin-dominant dissolved organic matter (DOM) with high biotransformation potential was a favored substrate for all PCB degraders, which led to no stimulation of PCB degradation in MS. Differently, high-aliphatic SOM in US and IS promoted PCB bioavailability. The high/low biotransformation potential of multiple DOM components (e.g., lignin, condensed hydrocarbon, unsaturated hydrocarbon, etc.) in US/IS further resulted to the enhanced PCB degradation by B. diazoefficiens USDA 110 (up to 30.34%) /all PCB degraders (up to 17.65%), respectively. Overall, the category and biotransformation potential of DOM components and the aromaticity of SOM collaboratively determine the stimulation of GO-assisted bacterial agent on PCB degradation.


Asunto(s)
Bifenilos Policlorados , Contaminantes del Suelo , Bifenilos Policlorados/análisis , Suelo , Lignina , Contaminantes del Suelo/metabolismo , Biodegradación Ambiental , Microbiología del Suelo
16.
Amino Acids ; 55(3): 337-348, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36617370

RESUMEN

To design and develop novel antimicrobial agents, a series of phthalimide-triazine-based derivatives (6a-6e) were synthesized, characterized and evaluated for their potential antibacterial activities. The compounds were prepared through reaction of 6-phenyl-1,3,5-triazine-2,4-diamine with phthalimide moiety containing aliphatic amino acid. Structural analysis of the synthesized compounds was carried out by various characterization techniques such as FT-IR, 1H and 13C-NMR and mass spectroscopy. After the confirmation of the structure, the antibacterial screening of the synthesized compounds was performed against two strains of Gram-positive (Staphylococcus aureus, and Bacillus subtilis) and two strains of Gram-negative (Escherichia coli and Salmonella enteritidis) bacteria. The results of antimicrobial activity showed that compound 6d was the most active against all the tested strains of microorganisms with the MIC value 1.25 µg/µl. The synthesized compounds were docked into the binding sites of E. coli-DNA gyrase B and S. aureus-DNA gyrase complex to explore their theoretically binding mode and possible interactions of these ligands with these two targets. Docking study showed the importance of both hydrogen bonding and hydrophobic interactions as a key interaction with the targets. Based on the obtained results, the hybrid derivatives of triazine and phthalimide could be regarded as efficient candidates for further molecular developments of antimicrobial agents.


Asunto(s)
Girasa de ADN , Escherichia coli , Simulación del Acoplamiento Molecular , Girasa de ADN/metabolismo , Escherichia coli/metabolismo , Staphylococcus aureus , Espectroscopía Infrarroja por Transformada de Fourier , Antibacterianos/farmacología , Antibacterianos/química , Ftalimidas/farmacología , Aminoácidos , Triazinas/farmacología , Triazinas/química , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Relación Estructura-Actividad
17.
Bioresour Technol ; 368: 128359, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36423768

RESUMEN

This study aimed to evaluate the impacts of inoculation with bacterial inoculum containing three thermotolerant nitrifying bacteria strains on nitrogenous gas (mainly NH3 and N2O) emissions and bacterial structure during the sludge composting. The results of physicochemical parameters indicated that inoculation could prolong the thermophilic phase, accelerate degradation of organic substances and improve compost quality. Compared with the non-inoculated treatment, the addition of bacterial agents not only increased the total nitrogen content by 8.7% but also reduced the cumulative NH3 and N2O emissions by 32.2% and 34.6%, respectively. The bacterial inoculation changed the structure and diversity of the microbial community in composting. Additionally, the relative abundances (RA) of bacteria and correlation analyses revealed that inoculation increased the RA of bacteria involved in nitrogen fixation. These results suggested that inoculation of thermotolerant nitrifying bacteria was beneficial for reducing nitrogen loss, nitrogenous gas emissions and regulating the bacterial community during the composting.


Asunto(s)
Compostaje , Aguas del Alcantarillado , Estructuras Bacterianas , Bacterias , Nitrógeno
18.
Rev. méd. Maule ; 37(2): 23-27, dic. 2022. tab
Artículo en Español | LILACS | ID: biblio-1427980

RESUMEN

Introduction: Periprosthetic infection (PPI) is one of the most devastating complications of total knee arthroplasty (TKA). The incidence described in the literature is 2.4% and the most frequently isolated bacteria are Staphylococcus Aureus and Staphylococcus Coagulase-Negative (Gram positive). Polymicrobial infections represent between 10 to 37% and negative cultures between 7 to 15%. Methodology: Descriptive and retrospective study that consisted of reviewing the TKA database of the Regional Hospital of Talca during the 2018-2020 period, where knee PPIs were identified according to the diagnostic criteria validated in 2018. The cultures of patients diagnosed with PPI were reviewed, analyzing the antibiogram and resistance profile. Results: During 2018-2020, 459 TKAs were performed in our center, diagnosing 30 PPIs of the knee. 47% of PPIs were acute and 53% chronic. The results of the cultures were negative in 26.6%, 23.3% Methicillin Sensitive Staphylococcus Aureus; 13.3% Methicillin Resistant Staphylococcus Epidermidis and 13.3% of the cultures were polymicrobial. Discussion: Highlights the high resistance to methicillin, especially of Staphylococcus Epidermidis. This opportunistic pathogen has the ability to form a biofilm and, thanks to its genomic flexibility, rapidly acquires resistance to antibiotics. Polymicrobial infections have a synergistic effect that favors the persistence of the infection, which is why they will require a greater number of surgeries and prolonged antibiotic therapy. Pruebas especiales como la sonicación podrían aumentar las posibilidad de identificar al microorganismo. Conclusion: In these three years of follow-up, the PPI rate has been higher than reported annually in the literature. Gram-positive microorganisms continue to predominate, but with an increase in the rate of resistant to methicillin. Also, highlight the number of negative cultures. There would be a possible benefit theoretical in optimizing antibiotic prophylaxis in view of the large percentage of methicillin resistance and in seeking new ways to reduce negative cultures.


Asunto(s)
Humanos , Femenino , Anciano , Infecciones Relacionadas con Prótesis/cirugía , Infecciones Relacionadas con Prótesis/epidemiología , Artroplastia de Reemplazo de Rodilla/efectos adversos , Staphylococcus aureus , Estudios Retrospectivos , Biopelículas , Antibacterianos
19.
Bioresour Technol ; 362: 127848, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-36031129

RESUMEN

This study evaluated the coupling effects of sodium nitrate (SN) and sulfur-oxidizing bacterial agent (BA) on oxidizing reduced-state sulfur and altering the bacteria community in SN, BA, and SN + BA treatments, respectively. Results revealed that bacterial inoculation prolonged the thermophilic period, facilitated organics degradation and compost humification. Compared to the control group, SN + BA treatment reduced the cumulative H2S emissions and sulfur loss rate by 55.1 % and 15.7 %, respectively, and the nitrate reduction (used as electron donors) efficiency was enhanced by 7.8 % during the first week of composting. Bacterial inoculation altered the diversities and structure of the bacterial community by increasing the relative abundances of thermotolerant bacteria. Correlation analyses showed that the dominant phyla involved in nitrate-based sulfur-oxidizing reactions could be Firmicutes and Synergistota. These findings suggested the application viability of SN and BA to regulate the sulfur biotransformation and bacterial community in composting.


Asunto(s)
Compostaje , Bacterias , Estiércol , Nitratos , Suelo , Azufre
20.
Artículo en Inglés | MEDLINE | ID: mdl-35856134

RESUMEN

BACKGROUND: Peripartum antibiotics are commonly administered. Little is known of the attitudes of pregnant women toward peripartum antibiotics. AIM: We aimed to assess the awareness of and attitudes toward peripartum antibiotic use in Australian women. MATERIALS AND METHODS: We surveyed post-partum women at three hospitals over six months. Women reported if they received antibiotics 48 h either side of delivery and responded to statements assessing attitudes to peripartum antibiotic use. Administered antibiotics were recorded. We reported the proportion receiving antibiotics and the proportion aware of receiving them. Participants responded on five-point Likert scales and selected side effects of concern. RESULTS: Participants responding were 248 of 299 (83%, Royal Brisbane and Women's Hospital), 56 of 106 (53%, Caboolture Hospital) and 17 (Redcliffe Hospital, denominator not recorded). Of 183 (57%) receiving antibiotics, 134 (73%) received them pre-delivery only, 18 (10%) post-delivery only and 31 (17%) pre- and post-delivery. Pre-delivery, the most common indication was pre-incisional prophylaxis for caesarean delivery (93 of 160 responses, 58%). Seventy-nine (51%, 156 responses) of those receiving pre-delivery antibiotics were aware. Of 49 women receiving post-delivery antibiotics, 36 (73%) were aware. Most agreed they were worried that pre-delivery antibiotics would affect their baby (198, 62%) and 160 (50%) were concerned about effects on their own microbiome. Most (204, 65%) agreed they would rather not take antibiotics while breastfeeding. CONCLUSION: Many women were unaware of receiving pre-delivery antibiotics. Most had concerns about side effects. Improved communication regarding peripartum antibiotic use would improve patient-centred care.

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